This invention relates generally to a cleaning apparatus, and more particularly concerns a performance monitor for a brush cleaner.
Electrostatic brush cleaners, like most photoreceptor cleaners, normally have two levels of performance--pass or fail. Subjective attempts to categorize the failures as hard failures or marginal failures have been made, but no indication of how well a cleaner cleans has been available other than counting particles of toner which remained on the photoreceptor after cleaning. Particle counting is extremely tedious and requires a statistical sampling to represent the cleaner performance due to the very low toner densities on the photoreceptor.
Electrostatic brush cleaners typically have soft failure modes. Soft failure modes occur when the performance of the cleaner gradually degrades with time due to various causes of wear. If the cleaner abruptly ceases to function, the causes are normally attributed to catastrophic failures of parts, such as fractures, or loss of bias voltages due to power supply failures or broken wire harnesses. Soft failures can result from normal toner accumulation in the brush which decreases the capacity of the brush to handle high toner input masses. Brush fiber set over time will decrease interference to the photoreceptor, eventually resulting in failures with high toner inputs. Filming of a detoning roll surface or contamination of the brush fiber tips gradually decreases the cleaning capability of an electrostatic brush. Toner or other material becoming impacted on the brush fiber tips or wear of the conductive coating from the tips would also gradually degrade cleaner performance.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,229,817 to Lange et al. discloses a cleaning apparatus that includes a rotatable member adapted to contact the charge retentive surface for removing the residual material therefrom, and a motor for rotating the rotatable member. The cleaning apparatus further includes a motor controller for transmitting an electrical signal to the motor, and a machine controller for monitoring the electrical signal to measure the extent of wear to which the rotatable member was subjected. In another aspect of the disclosed embodiment, the cleaning apparatus includes a conductive cleaning member, disposed proximate the charge retentive surface, for generating an electrostatic field to remove the residual material from the charge retentive surface. Additionally, there is provided a power supply for transmitting an electrical signal to the conductive cleaning member, and an electrical circuit for monitoring the electrical signal to measure the extent of wear to which the conductive cleaning member has been subjected.